Well packer

ABSTRACT

A well packer adapted to be used for cementing operations and the like in a well, wherein the packer includes hold-down slips to hold the packer sealing means and packer slips in the set position, and such hold-down slips are actuated by fluid from the annulus so as to be isolated from the bore of the packer mandrel to keep the hold-down slips free of cement or other fluids in such bore which might cause a malfunctioning of the hold-down slips.

United States Patent [191 Davis, Jr.

[ WELL PACKER [76] Inventor: Philip E. Davis, .lr., PO. Box

35729, Houston, Tex. 77035 22 Filed: .lune23,11972 211 App1.N0.: 265,655

[52] US. Cl. 166/120, 166/130 [51] Int. Cl E211) 23/06 [58] Field of Search 166/120, 129, 130, 166/134, 138

[56] References Cited UNITED STATES PATENTS 3,426,846 2/1969 {Young 166/129 3,422,899 l/1969 Brown 166/129 3,249,149 5/1966 McGowen 166/130 X 3,586,106 6/1971 Conrad 166/120 Clark et a1. 166/129 [451 Jan. 15, 1974 3,253,656 5/1966 Brown 166/129 3,412,799 11/1968 Ellis 166/120 3,645,334 2/1972 McGill 166/129 X Primary Examiner-David H. Brown Att0rneyPravel, Wilson & Matthews [57] ABSTRACT A well packer adapted to be used for cementing operations and the like in a well, wherein the packer includes hold-down slips to hold the packer sealing means and packer slips in the set position, and such hold-down slips are actuated by fluid from the annulus so as to be isolated from the bore of the packet mandrel to keep the hold-down slips free of cement or other fluids in such bore which might cause a malfunctioning of the hold-down slips.

12 Claims, 9 Drawing Figures WELL PACKER BACKGROUND OF THE INVENTION The field of this invention is well packers, particularly well packers of the squeeze-type.

So far as is known, well packers such as the one shown in U. S. Pat. No. 3,428,123, having hold-down slips have been actuated by fluid directed from the bore of the packer mandrel which sometimes creates a problem in operating such hold-down slips especially when such fluid is a cement or similar fluid that is thick and is subject to hardening, or is a solid carrying fluid such as used for sand fracing.

SUMMARYOF THE INVENTION The present invention relates to a well packer which has a fluid by-pass for by-passing fluid in the annulus around the packer sealing means to prevent the packer from floating as it is run into the hole. Hold-down slips are provided with the packer and are actuated by fluid in the annulus from the area below the packer so as to isolate the hold-down slips from the fluids in the tubing for thereby preventing cement and the like from causing a malfunctioning of the hold-down slips. The packer is relatively short in length and is easily and automatically set, preferably by right hand rotation. Well pressure and possible corkscrewing of the tubing supporting the packer will not open the by-pass after the hold-down slips are set. Also, with the packer of this invention, tubing shortening or shrinkage due to temperature reductions will not release the packer or the holddown slips when pressure is maintained in the tubing.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. IA, 18 and 1C are vertical sectional views, partly in elevation, showing the upper, intermediate and lower portions, respectfully, of the well packer of this invention in the normal ruining-in position;

FIG. 2 is a cross-sectional view taken on line 22 of FIG. 1A;

FIG. 3 is a cross-sectional view taken on line 3-3 of FIG. 1A;

FIGS. 4A and 4B are partial sectional views, partly in elevation, illustrating the apparatus of FIGS. IA-lc after the packer slips have been set, but prior to the setting of the packer sealing means; and

FIG. 5A and FIG. 5B are partial sectional views, partly in elevation, illustrating only the upper portions of the well packer of this invention as illustrated in FIGS. lA-1C, but showing the packer sealing means and the hold-down slips in their set positions in the well pipe.

DESCRIPTION OF THE PREFERRED EMBODIMENT One embodiment of the well packer of this invention is illustrated in FIGS. 1A, 1B and 1C, showing the upper, intermediate and lower portions ofsuch packer, respectively. The packer is lowered into a well pipe P on a tubing string T. Broadly, the packer of this invention includes gripping slips G, packer sealing means S and a hold-down means or slips H. As will be explained in detail, a by-pass for fluid is provided so that the fluid in the annulus between the well pipe P and the tubing string T may flow around the sealing means S during the running in of the packer so as to prevent a floating or buoyancy of the packer as it is run into the well pipe P. Also, the flow through such by-pass means is controlled by a valve means V, as will be explained in detail so as to close off such by-pass and direct the fluid from below the sealing means S through the by-pass to the hold-down slips H for'actuating same to thereby lock the packer in the set position with the slips G and the sealing means S in their set positions in the pipe P.

Considering the invention more in detail, the packer of this invention includes a mandrel 12 which extends for substantially the full length of the packer and which has its upper end connected at threads 12a or other suitable connecting means to an adapter sub 14 which has the hold-down slips H therewith. The adapter sub 14 is connected by threads 14a or other suitable means to the lower end of the tubing string T which extends to the surface of the well in the known manner.

A lower tubular packer body 15 (FIG. 1C) is disposed at the lower end of the packer and is provided with a J-slot 16 having a J notch 16a, and an outlet slot 16b leading from the J-slot 16a. A connecting pin 12b is secured to or is integral with the mandrel 12 and is adapted to extend into the J -slot 16 so as to connect the body 15 and the mandrel 12 together when the pin 12b is in the J portion 16a as illustrated in FIG. 1C. Upon v a righthand rotation of the mandrel 12 relative to the body 15, the pin 12b moves automatically out of the J- slot 16a and upwardly until it enters the slot 16b at which time the mandrel 12 may move downwardly relative to the body 15 as the pin 12b moves in the slot 16b, for a purpose to be hereinafter described.

The packer body 15 is provided with a wedge or expander 150, which is preferably annular and has a downwardly and inwardly inclined expander surface or surfaces 15b therewith for engagement with pipe gripping slips 18 having gripping teeth 18a on the external surface thereof for gripping engagement with the interior of the pipe P for supporting the packer in the pipe P as-will be more evident hereinafter. A plurality of such gripping slips 1%, preferably three in number are circumferentially spaced with respect to each other and are disposed in windows 20a of a sleeve 20 and above the shoulder at the upper end of the body 15. Each of such slips 18 has inner downwardly inclined surfaces 18b which are adapted to co act with the inclined surfaces 1l5b so as to urge the slips 18 radially outwardly into the gripping engagement with the pipe P.

The sleeve 20 is secured to the body 15 by a plurality of retaining screws 20b or other suitable securing means. The upper ends of the gripping slips 18 are also confined with their upper ends by retaining screws 200 or other suitable securing means. Leaf springs 20c are secured to the sleeve 20 by screws 20d or other suitable securing means and each of such springs 20c is adapted to fit into a longitudinal groove 18c for applying resilient force to the gripping members 18 to maintain them in their inward retracted postion with the surfaces 18b constantly in contact with the surfaces 15b. Upon an outward radial movement of thegripping members 18 by reason of the wedging action with the expander member 15a, the springs 20c yield to permit such radial movement. i

Suitable friction means such as the flexible bow springs 22 (FIG. 1C) are secured to the body 15 by screws 22a or other suitable securing means, and the lower ends 22b are free to slide as the springs 22 resiliently engage the inner wall of the pipe P. The lower ends 22b of the friction springs 22 are confined by a keeper ring e which is connected to the sleeve 20 by a plurality of screws 20f or other suitable securing means. It should be understood that any other suitable friction means such as friction blocks or shoes of conventional construction may be used in place of the bow springs 22 so long as the friction means constantly engages the inner wall of the pipe P. It will be understood that normally there will be a plurality of such friction means 22 so as to tend to also centralize the packer within the pipe P.

The upper end of the packer body 15 is connected at upper threads 15d (FIG. 113) to a sleeve 23 which is connected by threads or other suitable means to a metal ring 24. A plurality of openings 152 are formed in the upper portion of the packer body 15, and it is to be noted that the body 15 is formed with a larger internal diameter as indicated at 15f as compared to the inner diameter of the body 15 therebelow to thereby serve as a portion of a by-pass channel or passage, as will be more evident hereinafter. The sleeve 23 also is spaced from the mandrel 12 so as to form an annular passage 25 which is a continuation of the passage above the by-pass openings 15c and it communicates with a passage 25a within the bore of a telescoping tube 27 which is a part of the packer seal means S. A plurality of packer rings 30 formed of rubber or other suitable resilient material (FIGS. 1A and 1B) are mounted on the tube 27, preferably with metal rings 31 therebetween.

A seal setting sleeve 35 is threaded or is otherwise connected to the upper end of the tube 27 at threads 35a and such sleeve 35 is disposed above the upper packer seal member 30 for engagement therewith. The sleeve 35 has its inner bore spaced radially from the external surface of the tube 12 so as to form a continuation of the passage 25 as indicated at 35b, which is thus a continuation of the by-pass passage 25 therebelow. The sleeve 35 has a lower shoulder 35c which is adapted to be engaged by the upper ends of a plurality of spacer rods 36 which are welded to the mandrel 12 and are movable therewith to effect a release of the packer sealing means S, as will be explained hereinafter. As seen in FIG. 3, the rods 36 are welded or are otherwise affixed to the mandrel l2 and are circumferentially spaced so that they do not interfere with the annular passage means 250 between the mandrel l2 and the inner surface of the sleeve 27.

The actuating sleeve 35 has an upper annular surface 35d which is adapted to be engaged by an annular shoulder 140 on the sub 14 for applying downward force to the sleeve 35 to set the packer as will be explained. Also, the sleeve 35 is provided with a counterbore or enlarged diameter 35s at its upper end which serves to provide a sealing surface against which a valve seal ring 37 of the valve V is adapted to engage for shutting off the by-pass of fluid upwardly through the open upper end of the sleeve 35 during the running-in of the packer in the pipe P. Thus, when the valve seal 37 which is made of any suitable sealing material such as chevron packing, is out of engagement with the internal cylindrical surface 35s, a by-pass of fluid inwardly and around the sealing means S is permitted so as to prevent a floating or buoyancy of the packer as it is lowered into the well. The hold-down slips H include a plurality of gripping slips 40 having gripping teeth 40a which are adapted to engage and grip with the inside surface of the pipe P. A plurality of such gripping members 40 are preferably provided in a circumferential arrangement, usually three in number and each is mounted in a pocket or recess 14b in the sub 14. Each gripping member 40 acts like a piston and it preferably includes a ring 40b therewith formed of rubber or similar material which is in sealing engagement with the inside of the recess 14b so that fluid pressure acting on the rear surface 40c of each gripping member 40 urges same outwardly into gripping engagement with the pipe P. The fluid pressure is supplied to the recesses 14b by a plurality of longitudinally extending passages 14c (FIG. 1A) which are in communication with lateral passages 14d (FIG. 2). Each of the longitudinal passages l4c communicates with one of the lateral passages l4d, and each lateral passage 14d is in communication with at least two of the pockets 14b as seen in FIG. 2. Since all of the pockets 14b are thus interconnected by the passages 14d, fluid may be supplied to all of the gripping members 40 through only one of the longitudinal passages 140, should one or more of the other longitudinal passages 14c become plugged with some foreign matter.

The gripping members 40 are retained in position and are normally held in the retracted position by retaining screws 45 which are screwed into the adapter 14. Also, leaf springs 46 are connected to the adapter 14 by screws 46a and these assure the gripping members 40 are retained in their retracted position until a sufficient fluid pressure is applied from the passages 14c and 14d to urge the gripping members 40 outwardly against the resistance of such springs 46.

In' the operation or use of the well packer of this invention, it is lowered into the well pipe P on the tubing string T, with the releasable connecting pin 12b in the .I portion of the J-slot 16 (FIGS. lA-lC). The slips G, the packer sealing means S and the hold-down slips H are all in the retracted position out of engagement with the inner wall or surface of the well pipe P. The friction springs 22 or other friction means are in contact with the inner surface or wall of the well pipe P as the packer is lowered into the pipe P to the desired location therein. It is to be noted that during the lowering of the packer P, the well fluid externally of the packer by-passes the packer sealing members 30 by flowing upwardly through the by-pass ports 15e and the inner by-pass passage which includes the passage spaces 25, 25a and 35b, as previously explained. The valve V is in the open position so that it does not restrict the by-pass of such fluid around the sealing means S and therefore, there is no tendency for the well packer to float or be buoyed up by the well fluid as a result of restriction at the packer sealing means S. Such by-pass therefore facilitates the rate of lowering of the packer even though the well pipe P is full of fluid.

When the packer has reached the desired elevation in the pipe P, the lowering of the packer is discontinued and the tubing string T is rotated in a righthand direction to thereby also rotate the mandrel 12 in a righthand direction which automatically moves the connecting pin 12b upwardly along the guide of the .I-slot portion 16a until it reaches the vertical open slot 16b, at which time the weight of the tubing string T and the mandrel and the parts therewith cause the mandrel 12 to move downwardly relative to the rest of the packer so that the pin 12b moves downwardly and out of the slot 16b as illustrated in FIG. 4B.

The sub14 likewise moves downwardly with the mandrellZ so as to move the valve V into the closed position (FIG. 4A), bringing the shoulder 14a into contact with annular surface or shoulder 35d to thereby apply the weight of the tubing string to the sleeve 35 and through the packer sealing means S to the expander 15a for causing the expander 15a to move downwardly relative to the gripping members 18 which are held against downward movement by the friction springs 22. The coaction between the inclined surfaces 15b and 18b causes an outward radial movement of the gripping members 18 to set the slips by engaging the gripping teeth 18a with the inner surface of the wall or pipe P (FIG. 48).

It should be noted that although the valve V is closed I at the time of the setting of the slips G, and the by-pass inwardly of the sealing means S is thus closed off, there is still fluid pressure in the tubing externally of the holddown slips H which tends to equalize the pressure on each side thereof so that the hold-down slips H do not set to any extent at that time. However, upon a continued downward movement of the tubing string T after the slips G are set, the sealing means S is then set in its sealing position (FIG. 5B). The sealing means S is thus set in its sealing contact with the inside surface of the pipe P because the downward movement of the packer body 15, sleeve 23 and ring 24 are prevented after the expander 150 had wedged gripping slips 18 into their set position. The inner tube 27 telescopes and moves downwardly from the position shown in FIG. 13 to the position shown in FIG. 58 with its lower shoulder 27a displaced below the shoulder 24a of the ring 24.

After the packing rings 30 have been compressed into their sealing or set position shown in FIG. 5B, the

- fluid pressure in the well externally of the packer can no longer communicate withthe exterior of the holddown slips H and therefore the only fluid pressure acting on the gripping members 18 of the hold-down slips H is from the by-pass fluid entering the ports 15e from below the packer sealing means S. Such fluid pressure acts to urge the gripping members 40 outwardly into gripping engagement with the inside surface of the pipe P. It is to be noted that the gripping teeth 400 are disposed so that they bite into the wall of the pipe P at an angle to resist upward movement of the gripping members 40 so as to thereby prevent an inadvertent release of the packer sealing means S and the packer slips G- from their set position.

It is also to be noted that the hold-down means 40 is actuated by the fluid pressure in the annulus of the well between the tubing string T and the pipe P rather than by the fluid within the bore of the tubing string T or the mandrel 12. Suchmanner of operation reduces the danger of introducing cement or the heavier fluids into the passages 14c and 14d which communicate with the rear of the gripping members 40 for actuating same, thereby reducing the possibility of the lines 14c and 14d becoming plugged by the cement or other heavy fluids which are normally present in the bore of the tubing string T, particularly during cementing operations.

By reason of construction of the valve V, even though the tubing string tends to corkscrew or twist, the valve V will not inadvertently become opened after it has been closed and the hold-down slips H have been set. Well pressures may increase in the tubing string T and below the sealing means S without unsetting or releasing the valve V so that the packer is not prematurely released. Similarly, even though there is shrinkage or shortening of the tubing due to temperature reductions or other changes which might cause other packers to release, the packer of this invention will not release under such circumstances.

To release the packer from its set position to remove same from the well, the hold-down means H is first released by bleeding off the tubing pressure so as to be zero or equalized internally and extemally of the gripping members 40. In some cases; pressure is applied in the annulus above the hold-downgripping members 40 to equalize the pressure acting thereon. After the pressure has thus been equalized on the gripping members 40, the tubing string T is raised upwardly to initially cause the upper ends of the rods 36 to engage the shoulder 350 so as to exert the lifting force on the sleeve 35 as the tubing string T is moved upwardly to thereby relieve the pressure on the sealing rings 30 from the sleeves 35 as the tubing string T is pulled upwardly. The release of the contact between the shoulders 14a and 35d also relieves the weight from the sealing means S to allow the resiliency of the sealing mem bers 30 to act to urge them upwardly and release same from their set position.

Continued upward movement of the tubing string T and the mandrel 12 also causes an upward travel of the telescoping sleeve 27 and an engagement of the shoulder 27a with the shoulder 24a to thereafter lift the tube 23 and the packer body 15 therebelow upwardly to pull the expander or wedge section 15a upwardly relative to the gripping slips 18 to thereby release the expanding force on the gripping slips 18. The resiliency of the leaf springs 20c thus returns the gripping members 18 to their retracted position so that they may then be withdrawn upwardly in the well.

It is to be noted that the pin 12b is guided into the vertical slots 16b by a curved surface 15g on the lower portion of the packer body 15 so that the pin 12b returns to the J-slot l6 and may be reset with the pin 12b in the J portion 16a after the packer slips G have been released, if desired. The resetting is accomplished by a slight amount of lefthand rotational movement of the tubing string T after the slips G have been released to their set position and then the packer can be moved upwardly or downwardly in the well as desired to any suitable elevation. I

Although this invention has been described for setting by a right rotation, it will be understood that the J-slot 16 can be reversed for setting by left hand rotation if desired. It should also be understood the packer may be of the pin type or isolation type, wherein slips such slips G are not employed. In such cases, the packer sealing means S is held down solely by the slips H.

The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape, and materials as well as in the details of the illustrated construction may be made without departing from the spirit of the invention.

I claim:

1. A well packer for use in a well, comprising:

a mandrel having a central bore forming the central bore of the packer and adapted to be connected to a tubing string for lowering into a well pipe;

packer sealing means on said mandrel for sealing engagement with the pipe to seal off the annulus between the tubing string and the well pipe;

hold-down slips integrally connected with said mandrel for longitudinal movement together and with the tubing string at all times and for gripping engagement with the well pipe for preventing a premature release of said packer sealing means;

said mandrel having no passages therethrough above said sealing means;

fluid by-pass means with said mandrel for by-passing annulus fluid around said sealing means; and

valve means mounted on said mandrel for closing said fluid by-pass means above said sealing means after said packer sealing means is in sealing engagement with the well pipe.

2. The packer set forth in claim 1, including:

packer slip means on said mandrel;

a releasable .l-slot connection means connecting said packer slip means to said mandrel and being releasable upon a rotation of said mandrel relative to said slip means; and

friction means engageable with the well pipe for preventing rotation of said slip means upon a rotation of said mandrel for releasing said J-slot connection means.

3. The packer set forth in claim 1, wherein said valve means includes an annular valve seal, and also includmg:

an annular valve sleeve mounted above said packer sealing means for communicating with said fluid by-pass means and having an inner bore of a diameter to receive said annular valve seal in sealing engagement therewith.

4. The packer set forth in claim 1, including: packer slip means slidably mounted on said mandrel for supporting said mandrel in the well pipe; and said hold-down slips having fluid passage means for communicating with said fluid by-pass means when said valve means has closed off said by-pass means above said sealing means for thereby directing the fluid from below said sealing means through said by-pass means to said hold-down slips for actuating same.

5. The packer set forth in claim 4, including:

means separating the bore of said mandrel and the tubing string from said hold-down slips for thereby isolating said hold-down slips from the fluid in said bore.

6. The packer set forth in claim 4, including:

support means for said valve means and said holddown slips having connection with said mandrel for movement therewith to and from the position of said valve means wherein said by-pass means is closed off above said sealing means.

7. The packer set forth in claim 4, wherein:

said hold-down slips includes a plurality of gripping slips for engagement with the well pipe to prevent an inadvertent release of said sealing means and said packer slip means from their set positions in engagement with the well pipe; and

said fluid passage means includes a plurality of fluid passages from said by-pass means to said gripping slips for providing alternate flow routes for fluid to each of said gripping slips in the event one or more of the fluid passages becomes plugged.

8. A well packer for use in a well, comprising:

a mandrel having a central bore forming the central bore of the packer and adapted to be connected to a tubing string for lowering into a well pipe;

7 packer sealing means on said mandrel for sealing engagement with the pipe to seal off the annulus between the tubing and the well pipe;

hold-down slips mounted with said mandrel for longitudinal movement together and with the tubing string at all times and operable by fluid pressure from externally of the tubing string for gripping engagement with the well pipe;

means separating said hold-downslips from the bore of said mandrel and the tubing string; and fluid passage means communicating said hold-down slips with fluid in the annulus between the tubing and the well pipe for actuating same after the sealing means have been set in engagement with the well pipe.

9. The packer set forth in claim 8, including:

packer slip means on said mandrel for gripping engagement with the well pipe for supporting said mandrel in the well. 10. The packer set forth in claim 8, including: fluid by-pass means with said mandrel for by-passing fluid in the annulus around said sealing means; and

valve means mounted on said mandrel for closing said fluid by-pass means above said sealing means after said packer sealing means is in sealing engagement with the well pipe.

11. The packer set forth in claim 10, wherein:

said hold-down slips includes a plurality of gripping slips for engagement with the well pipe to prevent an inadvertent release of said sealing means and said packer slip means from their set positions in engagement with the well pipe; and

said fluid passage means includes a plurality of fluid passages from said by-pass means to said gripping slips for providing alternate flow routes for fluid to each of said gripping slips in the event one or more of the fluid passage becomes plugged.

12. The packer set forth in claim 10, wherein said valve means includes an annular valve seal, and also including:

an annular valve sleeve mounted above said packer sealing means for communicating with said fluid by-pass means and having an inner bore of a diameter to receive said annular valve seal in sealing engagement therewith. 

1. A well packer for use in a well, comprising: a mandrel having a central bore forming the central bore of the packer and adapted to be connected to a tubing string for lowering into a well pipe; packer sealing means on said mandrel for sealing engagement with the pipe to seal off the annulus between the tubing string and the well pipe; hold-down slips integrally connected with said mandrel for longitudinal movement together and with the tubing string at all times and for gripping engagement with the well pipe for preventing a premature release of said packer sealing means; said mandrel having no passages therethrough above said sealing means; fluid by-pass means with said mandrel for by-passing annulus fluid around said sealing means; and valve means mounted on said mandrel for closing said fluid bypass means above said sealing means after said packer sealing means is in sealing engagement with the well pipe.
 2. The packer set forth in claim 1, including: packer slip means on said mandrel; a releasable J-slot connection means connecting said packer slip means to said mandrel and being releasable upon a rotation of said mandrel relative to said slip means; and friction means engageable with the well pipe for preventing rotation of said slip means upon a rotation of said mandrel for releasing said J-slot connection means.
 3. The packer set forth in claim 1, wherein said valve means includes an annular valve seal, and also including: an annular valve sleeve mounted above said packer sealing means for communicating with said fluid by-pass means and having an inner bore of a diameter to receive said annular valve seal in sealing engagement therewith.
 4. The packer set forth in claim 1, including: packer slip means slidably mounted on said mandrel for supporting said mandrel in the well pipe; and saId hold-down slips having fluid passage means for communicating with said fluid by-pass means when said valve means has closed off said by-pass means above said sealing means for thereby directing the fluid from below said sealing means through said by-pass means to said hold-down slips for actuating same.
 5. The packer set forth in claim 4, including: means separating the bore of said mandrel and the tubing string from said hold-down slips for thereby isolating said hold-down slips from the fluid in said bore.
 6. The packer set forth in claim 4, including: support means for said valve means and said hold-down slips having connection with said mandrel for movement therewith to and from the position of said valve means wherein said by-pass means is closed off above said sealing means.
 7. The packer set forth in claim 4, wherein: said hold-down slips includes a plurality of gripping slips for engagement with the well pipe to prevent an inadvertent release of said sealing means and said packer slip means from their set positions in engagement with the well pipe; and said fluid passage means includes a plurality of fluid passages from said by-pass means to said gripping slips for providing alternate flow routes for fluid to each of said gripping slips in the event one or more of the fluid passages becomes plugged.
 8. A well packer for use in a well, comprising: a mandrel having a central bore forming the central bore of the packer and adapted to be connected to a tubing string for lowering into a well pipe; packer sealing means on said mandrel for sealing engagement with the pipe to seal off the annulus between the tubing and the well pipe; hold-down slips mounted with said mandrel for longitudinal movement together and with the tubing string at all times and operable by fluid pressure from externally of the tubing string for gripping engagement with the well pipe; means separating said hold-down slips from the bore of said mandrel and the tubing string; and fluid passage means communicating said hold-down slips with fluid in the annulus between the tubing and the well pipe for actuating same after the sealing means have been set in engagement with the well pipe.
 9. The packer set forth in claim 8, including: packer slip means on said mandrel for gripping engagement with the well pipe for supporting said mandrel in the well.
 10. The packer set forth in claim 8, including: fluid by-pass means with said mandrel for by-passing fluid in the annulus around said sealing means; and valve means mounted on said mandrel for closing said fluid by-pass means above said sealing means after said packer sealing means is in sealing engagement with the well pipe.
 11. The packer set forth in claim 10, wherein: said hold-down slips includes a plurality of gripping slips for engagement with the well pipe to prevent an inadvertent release of said sealing means and said packer slip means from their set positions in engagement with the well pipe; and said fluid passage means includes a plurality of fluid passages from said by-pass means to said gripping slips for providing alternate flow routes for fluid to each of said gripping slips in the event one or more of the fluid passage becomes plugged.
 12. The packer set forth in claim 10, wherein said valve means includes an annular valve seal, and also including: an annular valve sleeve mounted above said packer sealing means for communicating with said fluid by-pass means and having an inner bore of a diameter to receive said annular valve seal in sealing engagement therewith. 